There is going to be some unseasonably cold weather the next few days. It could be a colony killer. It may be a good idea to put a pail of syrup on the hive.
If the colony can take it down, the bees will put the syrup around their brood. Having syrup around the brood will make it easy for the bees to survive this cold snap.
If bees have to move a frame or two away from the brood to get honey, they may not be able to get enough honey to keep the brood warm and the colony may starve.
The feeder will be above the colony and more than likely will not freeze. The heat of the colony should keep it liquid.